Any movie about the infamous General George S. Patton would have to be an epic just to contain his outsized personality. George C. Scott captures the man's obsessive lust for the glory of war, in addition to his more eccentric idiosyncrasies such as a love of poetry and a belief in reincarnation. The battle scenes are all from a general's point-of-view, which makes this a unique and troubling look at war.
If ever there was a movie that defines the term "war epic," it's this one. Francis Ford Coppola brings his special kind of madness to Vietnam, to depict the story of a soldier sent way up the river to eliminate a former United States colonel who's gone insane and is leading a cult of natives to worship him as a god. The hallucinogens and bloody violence follow in nearly equal measure, and after it's over it's up to you to make sense of it all. Have fun!
Akira Kagemusha," a Shakespearean look at feudal Japan in which a famous warlord dies only to be replaced by a Doppelganger in order to maintain his rule. Nobody does violent battle scenes quite like Kurosawa, and "Kagemusha" has some of the best of his career.
Sometimes if you're in the mood for a war epic you just want to watch some guys kick ass for a while. If that's the case, check out "Eastern Condors" from legendary Hong Kong director Sammo Hung. It's not realistic by any stretch, but the story about a group of Chinese soldiers sent on a near-suicide mission to Vietnam to destroy an American explosives cache is chock-full of amazing stuntmen making full contact in the fight scenes. It's a whole new kind of "epic."